Nitazoxanide (2-(acetolyloxy)-N-(5-nitro-2-thiazolyl) benzamide) is a compound having the following structure:

Tizoxanide is the active circulating metabolite of nitazoxanide.
The preparation and uses of nitazoxanide are disclosed, for example, in U.S. Pat. No. 3,950,351 to Rossignol.
Pharmaceutical compositions containing nitazoxanide and its metabolite, tizoxanide, were originally developed and marketed for treating intestinal parasitic infections. However, nitazoxanide, tizoxanide and various analogues thereof have been shown to have activity against various intracellular protozoan infections, viral infections, including influenza and hepatitis, and cancers. See U.S. Pat. Nos. 8,524,278, 8,124,632, 7,645,783, 7,550,493, 7,285,567, 6,117,894, 6,020,353, 5,968,961, 5,965,590, 5,935,591, and 5,886,013, and U.S. application Ser. Nos. 12/184,760, 12/656,704, 12/821,571, 12/777,383, 13/284,242, 13/471,948, which are herein incorporated by reference in their entirety.
Furthermore, nitazoxanide, tizoxanide and various analogues thereof are capable of stimulating an immune response in subjects, which can result in treatment or prevention of an intracellular protozoan infection, a viral infection or a cancer.
Following oral administration of nitazoxanide or mixtures of nitazoxanide plus tizoxanide in humans, these compounds are partially absorbed from the intestinal tract, and nitazoxanide is rapidly hydrolyzed to form tizoxanide in plasma. Tizoxanide is glucurono-conjugated, and the drug is eliminated in urine and bile as tizoxanide or tizoxanide glucuronide. The half-life of tizoxanide in plasma is only approximately 1.5 hours.
Given this short half-life, and the relatively low bioavailability of nitazoxanide, tizoxanide and various analogues thereof there remains a need for compounds having a similar activity to nitazoxanide, tizoxanide and various analogues thereof, but with greater bioavailability.